Annuals or biennials; eglan-dular; usually pubescent, trichomes dendritic, sometimes glabrous distally. Stems erect, unbranched basally, branched distally, (1.3-)2-10.5 (-13.5) dm. Basal leaves: petiole 0.4-4.2 cm; blade pinnate, oblanceolate to obovate in outline, 1.5-6 cm, lateral lobes [2-4 (or 5) pairs], lanceolate, (5-22 × 1-5 mm), margins usually entire or crenate to incised, rarely lobed. Cauline leaves sessile or shortly petiolate; blade smaller distally, distal lobes often narrower, surfaces sparsely pubescent. Racemes considerably elongated in fruit. Fruiting pedicels divaricate to ascending or suberect, often straight, 3-9(-11) mm. Flowers: sepals spreading, yellowish, oblong, 0.9-1.5 mm, glabrous; petals oblanceolate, 1.1-1.8 × 0.4-0.6 mm; median filaments 0.8-1.4 mm; anthers 0.3-0.4 mm. Fruits divaricate to erect, fusiform, not torulose, (2-) 3-5(-6) × (0.8-)1-1.3 mm, (long-acute at both ends); valves each with obscure midvein; septum not veined; ovules 4-12 per ovary; style (0.2-)0.3-0.6(-0.8) mm, glabrous. Seeds uniseriate, light brown, ellipsoid, 1-1.4 × 0.6-0.8 mm. 2n = 14.

Flowering Jun-Aug. Disturbed areas in pinyon-juniper, dry hillsides, decomposed granite slopes, sagebrush, moist roadsides, open woods, fir-spruce or aspen communities, gravel and talus slopes; 1700-3400 m; Ariz., Calif., Colo., Nev., N.Mex., Oreg., Utah, Wyo.